A high-strength and high-fatigue-life steel for a cable, which comprises, in addition to Fe, the following chemical elements in percentages by mass: 0.90-1.00% of C; 0.90-1.50% of Si; 0.25-0.58% of Mn; 0.20-1.00% of Cr; 0.03-0.12% of V; and 0.0008-0.0025% of Ca. In addition, further provided are a wire rod made of the high-strength and high-fatigue-life steel for a cable and a preparation method for the wire rod.

The invention relates to a process for producing low-nitrogen crude steel. This process includes melting directly reduced iron and/or scrap in a melting furnace with arc resistance heating to give a metallic melt and a slag. The metallic melt is removed from the melting furnace and used to charge a converter. The metallic melt is refined in the converter to give liquid crude steel. The liquid crude steel is tapped having a nitrogen content [N] of not more than 50 ppm, especially of not more than 30 ppm.

The present disclosure provides a method of making non-grain oriented (NGO) electrical steel. The method includes tapping the liquid steel out of a primary steelmaking furnace. Deoxidizing the liquid steel before or after transferring the deoxidized liquid steel to a ladle metallurgy furnace. Removing sulfur at the ladle metallurgy furnace (LMF). Adding fluxes and deoxidizer to the ladle slag and/or skimming off ladle slag to prevent sulfur reversion. Transferring the liquid steel from the ladle metallurgy furnace to an RH degasser for carbon removal by blowing oxygen. Adding fluxes at the RH before oxygen blowing to fortify the bottom layer of the ladle slag to prevent sulfur reversion. The removal of oxygen and sulfur prior to transferring the liquid steel to the RH degasser facilitates nitrogen removal and prevents carbon pick up during the step of adding fluxes and arcing for sulfur removal if sulfur removal is carried out at the LMF after carbon removal at the RH degasser in the conventional process. Oxygen blowing at the RH also lowered the titanium pickup from the earlier desulfurization process. The ultra low levels of carbon, nitrogen, sulfur, and titanium in the NGO steel made using this method enabled the excellent magnetic properties achieved in the finishing NGO products.

A control process of inclusions in ultra-clean rare earth steel, wherein the content of rare earth elements REM in the ultra-clean rare earth steel, the total oxygen content T[O]m, the total sulfur content T[S]m in the steel, and the total oxygen content T[O]r in a rare earth metal or alloy added to the steel are controlled to satisfy the following formula: −500<REM−(m*T[O]m+n*T[O]r+k*T[S]m)<−30, where REM is the content of rare earth elements in the steel, in ppm; T[O]m is the total oxygen content in the steel, in ppm; T[O]r is the total oxygen content in a rare earth metal or alloy added to the steel, in ppm; T[S]m is the total sulfur content in the steel, in ppm; m is a first correction coefficient, with a value of 2-4.5;n is a second correction coefficient; and k is a third correction coefficient.

Fe—Ni—Cr alloy contains, in mass, from 0.001% to 0.050% of C, from 0.18% to 1.00% of Si, from 0.20% to 0.80% of Mn, 0.030% or less of P, 0.0001% to 0.0020% of S, from 12% to 21% of Ni, from 18% to 24% of Cr, from 0.20% to 1.50% of Mo, 0.30% or less of Cu, from 0.10% to 0.70% of Al, from 0.10% to 0.70% of Ti, from 0.002% to 0.015% of N, from 0.0001% to 0.0010% of B, from 0.0002% to 0.0030% of O, 0.002% or less of Ca, and from 0.0010% to 0.0150% of REM in total, said REM being composed of one or more elements selected from among La, Ce and Y, with the balance being made up of Fe and unavoidable impurities, and which satisfies formulae 1 and 2. Formula 1: 0.575xNi+1.25xCr+3.43xMo-39xP-5.3xAl-641xREM-1018xO≥20.0 Formula 2: 1.5xMn+41.3xSi+1469xS-1.67xAl-1.34xTi-150xO-620xREM≥5.0.

Provided is steel for a wind power gear with improved purity and reliability. The chemical components thereof comprise, in percentages by mass: 0.15-0.19% of C, ≤0.4% of Si, 0.5-0.7% of Mn, ≤0.012% of P, ≤0.006% of S, 1.5-1.8% of Cr, 0.28-0.35% of Mo, 1.4-1.7% of Ni, and 0.02-0.04% of Al, with the balance being Fe and inevitable impurities. A smelting method therefor comprises adding raw materials to a converter for primary melting, transferring same to a refining furnace for refining, carrying out continuous casting after vacuum degassing, and transferring same to a gas protection furnace for electroslag remelting. According to the present invention, a pure electroslag master batch is obtained by continuous casting, and the purity of the material is further improved by means of an electroslag remelting procedure; and the prepared steel material is used in a wind power gear, such that the flaw detection pass rate is significantly increased, large-particle inclusions in the steel material are significantly reduced, and the inclusions are fine and dispersed.

Provided is steel for a wind power gear with improved purity and reliability. The chemical components thereof comprise, in percentages by mass: 0.15-0.19% of C, ≤0.4% of Si, 0.5-0.7% of Mn, ≤0.012% of P, ≤0.006% of S, 1.5-1.8% of Cr, 0.28-0.35% of Mo, 1.4-1.7% of Ni, and 0.02-0.04% of Al, with the balance being Fe and inevitable impurities. A smelting method therefor comprises adding raw materials to a converter for primary melting, transferring same to a refining furnace for refining, carrying out continuous casting after vacuum degassing, and transferring same to a gas protection furnace for electroslag remelting. According to the present invention, a pure electroslag master batch is obtained by continuous casting, and the purity of the material is further improved by means of an electroslag remelting procedure; and the prepared steel material is used in a wind power gear, such that the flaw detection pass rate is significantly increased, large-particle inclusions in the steel material are significantly reduced, and the inclusions are fine and dispersed.

A method for producing steel strip, in particular hot strip in the form of coiled coils or in the form of folded individual sheets, in which a steel melt is first produced, this is then formed into a strand in a continuous casting system, the strand is then fed into a heating unit and the heated strand is then rolled into hot strip in a subsequent rolling mill. The casting of the strand, the passage through the heating unit, and the rolling take place in a continuous process. To be able to produce hot-rolled steel strips in the most energy-efficient way possible and to make these strips available for further processing into high-quality cold-rolled and, if necessary, coated strips, the invention provides that, first of all, a steel melt is produced.

Provided in the present application are a rare-earth microalloyed steel and a control process. The steel has a special microstructure, and the microstructure comprises a rare earth-rich nanocluster having a diameter of 1-50 nm. The nanocluster has the same crystal structure type as a matrix. The rare earth-rich nanocluster inhibits the segregation of the elements S, P and As on a grain boundary, and obviously improves the fatigue life of the steel. In addition, a rare-earth solid solution also directly affects a phase change dynamics process so that the diffusion-type phase change starting temperature in the steel changes at least to 2° C., and even changes to 40-60° C. in some kinds of steel, thereby greatly improving the mechanical properties thereof, and providing a foundation for the development of more kinds of high-performance steel.

Provided in the present application are a rare-earth microalloyed steel and a control process. The steel has a special microstructure, and the microstructure comprises a rare earth-rich nanocluster having a diameter of 1-50 nm. The nanocluster has the same crystal structure type as a matrix. The rare earth-rich nanocluster inhibits the segregation of the elements S, P and As on a grain boundary, and obviously improves the fatigue life of the steel. In addition, a rare-earth solid solution also directly affects a phase change dynamics process so that the diffusion-type phase change starting temperature in the steel changes at least to 2° C., and even changes to 40-60° C. in some kinds of steel, thereby greatly improving the mechanical properties thereof, and providing a foundation for the development of more kinds of high-performance steel.